Coffee preparation, that is, the process of producing a beverage using the coffee bean, typically requires four basic steps be performed: (i) the raw coffee beans are roasted; (ii) the roasted coffee beans are ground; (iii) the ground coffee beans are brewed, i.e., mixed with hot water for a period of time; and (iv) the liquid coffee beverage is separated from the unwanted grounds. Additional steps may include, for example, adding milk, sweetener, flavorings, and/or other additives to the brewed liquid. Typically, in much of the world, the roasted coffee beans are purchased by the user, who then performs the remaining steps. Various coffee brewing systems are known in the art, ranging from personal brewers such as drip coffee makers and French presses, to large commercial systems used for producing a dizzying array of flavored espresso-based beverages.
Ground coffee may be brewed in a number of different ways that may be categorized into four basic methods: (1) boiling, for example placing ground coffee into a cup and pouring hot water over the grounds, allowing the grounds to settle; (2) steeping, for example, placing ground coffee into a French press and waiting a few minutes before depressing the filtered plunger and pouring the brewed liquid into a cup; (3) filtration, for example drip brewing wherein the ground coffee is placed in a filter holder and hot water drips onto the coffee grounds into a carafe or the like; and (4) pressure methods, for making espresso wherein hot water typically between 91° C. and 96° C. is forced under a pressure of between eight and nine atmospheres through a lightly packed matrix or “puck” of finely ground coffee.
The different brewing methods have various disadvantages. For example, boiling and steeping methods require some time, typically 4-7 minutes, to produce an optimally flavored beverage. Filtration methods may be quicker, but do not produce the full bodied coffee that many consumers prefer, and/or may require more coffee grounds to produce an acceptable flavor. Espresso may be relatively quick, but requires relatively high pressures (8-9 atmospheres). Moreover, the high pressures are typically produced by steam, and the relatively high temperatures and pressures produce a very strong and distinctive flavor that some consumers may not prefer.
Similar considerations apply to other brewable beverages, such as teas and the like, which may be similarly brewed.
There is a need, therefore, for a system and method for brewing coffee and other beverages that retains the benefits associated with brewing coffee grounds that are suspended in the heated water, with the rapid brewing associated with pressure brewing methods.
It is important to consumers and producers alike, to be able to produce a consistent, high-quality brewed beverage, for example a coffee beverage. The quality of a brewed coffee depends on a number of different and often related parameters. The quality of a brewed coffee will typically depend on both the amount of coffee soluble components in the brewed liquid, and which of the coffee soluble components are present. If the coffee is under-brewed, for example, certain of the desirable flavor and aroma components may not be obtained from the coffee bean, resulting in an inferior product. Conversely, if the coffee is over-brewed, certain undesirable bitter soluble components may be dissolved in the liquid, again resulting in an inferior product. Conventionally, the quality of a brewed coffee liquid is characterized by measuring the total dissolved solids in the brewed beverage, and determining the percent of available solubles that were extracted from the coffee. However, the rate of extraction is not constant, so prior art quality determinations are made on the final brewed product. It may be difficult or inconvenient to obtain these parameters in the final product, which is typically provided to the end user, and may include flavorings or other additives at the time of dispensing.
A commercial retail vender of beverages, for example a coffee shop, will generally experience regular, relatively brief periods of peak demand. Moreover, during periods of high demand, many customers may be headed to work or have other time constraints such that their ability to wait for the beverage is severely constrained. Therefore, the customer may be forced to forego a desired beverage due to the wait time required, disadvantaging both the customer and the vender.
Also, periodically the vendor or other user may need larger volumes of coffee, such as carafes or higher volume portable containers. Customers may be unwilling to wait for a larger volume of coffee or other beverage to brew, however. Moreover, brewing the large volume demand may interfere with other customers seeking a single serving.
Many venders may attempt to accommodate such peak demand periods by preparing quantities of coffee in anticipation of the high demand. However, this strategy has the disadvantage that the beverage may become stale prior to being served, or may be wasted if the anticipated demand does not materialize. The strategy is also ineffective for accommodating irregular high-demand periods. Conventional coffee brewers require a long time to produce a large quantity of brewed coffee.
For these and additional reasons, it would be beneficial to have a brewing system that is capable of rapidly producing freshly brewed beverage on demand, and capable of producing larger quantities of brewed beverage in a reasonable amount of time.